Archaeologists have discovered India’s oldest stone-age tools, up to 1.5 million years old, at a prehistoric site near Chennai. The discovery may change existing ideas about the earliest arrival of human ancestors from Africa into India.

A team of Indian and French archaeologists has used two dating methods to show that the stone hand-axes and cleavers from Attirampakkam are at least 1.07 million years old, and could date as far back as 1.5 million years. In nearly 12 years of excavation, archaeologists Shanti Pappu and Kumar Akhilesh from the Sharma Centre for Heritage Education, Chennai, have found 3,528 artefacts that are similar to the prehistoric tools discovered in western Asia and Africa.

Their findings will appear tomorrow in the US journal Science. The tools fall in a class of artefacts called Acheulian that scientists believe were invented by the Homo erectus —ancestors of modern humans — in Africa about…